September 1, 2026 — A few years ago, biologist Brian Watson was looking for endangered mussels in Virginia’s Rock Island Creek when his assistant went around a bend and made a startling discovery. It wasn’t a rare mussel.
“There’s, like … a stone wall,” she shouted back to Watson. Then added, “That’s a dam.”
Standing 6 feet tall and stretching 55 feet across the creek, the dam was entirely unknown to them — appearing nowhere on maps or dam inventories.
But the dam wasn’t irrelevant to their project: It was taking a toll on mussels, as so many dams do. The biologists found shells of dead James River spinymussels, an endangered species, behind the structure.
“We assumed the mussels probably got washed down to the dam and then died as they got trapped,” said Watson, a mussel specialist for the Virginia Department of Wildlife Resources, noting that the sandy substrate and water depth behind the structure was unsuitable habitat.
It was one of more than 6,500 dams that dot more than 200,000 miles of waterways draining the Chesapeake Bay watershed. That’s an undercount. Many of them don’t appear on dam inventories. Research was required to learn that the one on Rock Island Creek was called the Baber’s Mill Dam, built in the early 1800s.
Large or small, dams create a host of problems. They alter habitat, block fish movement, change water temperatures, promote algal blooms and contribute to the decline of native species. Some are safety threats to people.
But the Baber’s Mill Dam no longer causes such problems.
By chance, an aquatic ecologist from the timber company Weyerhaeuser, which owned the property, contacted Watson about the dam a few months later. The state and company teamed up to remove the structure in April 2024.